1. Field of the Invention
The invention relates to an agitator mill comprising a grinding receptacle, which encloses a grinding chamber of a diameter D, which is closed downwards by a bottom, and which has a top cover and a vertical central longitudinal axis; an agitator, which has an agitator axis that is parallel to the central longitudinal axis, and which is equipped with agitator implements inside the grinding chamber; an agitator drive for rotary actuation of the agitator about the agitator axis; a grinding-stock supply which discharges into the grinding chamber; a partial filling of the grinding chamber with auxiliary grinding bodies of a diameter b which are movable in a bed of grinding stock and auxiliary grinding bodies in a direction of flow; and a device for grinding-stock suction and auxiliary-grinding-body separation, which leads out of the grinding chamber, which comprises a plunge pipe of an inside diameter d, which, by a bottom inlet, dips into the bed of grinding stock and auxiliary grinding bodies and from which a suction pipe discharges above the grinding receptacle, having a grinding-stock suction device.
2. Background Art
An agitator mill of the generic type is known from U.S. Pat. No. 4,998,678; it comprises a rotarily drivable grinding receptacle, with a seal that serves as a splash guard being provided between the grinding receptacle and a cover which is non-rotatably mounted on the machine stand, serving as a lid. These agitator mills cannot be operated at overpressure. Grinding-stock discharge is pressureless i.e., it takes place against atmospheric pressure.
In practice, numerous approaches towards separation of the auxiliary grinding bodies from the grinding stock after a grinding job have been made and published. Using screens and screen cartridges has become a familiar approach; however, they bear the risk of clogging and have a restricted surface. Providing rotary separating devices has also been known; they are comparatively complicated, tending to wear off in particular with abrasive grinding stock.
U.S. Pat. No. 2003/011663 A1 teaches an agitator mill of a design similar to the above, with the grinding-stock/auxiliary-grinding-body separating device being embodied in such a way that a plunge pipe is placed on an agitating disk with a gap being left through which to suck grinding stock. Such a design too tends to comparatively strong wear.